This invention relates to apparatus for reducing the likelihood of shoulder dislocations or subluxations occuring during athletic activity and, in particular is directed to apparatus to be worn by an athlete equipped with a standard shoulder pad assembly.
In athletic endeavors, the human body is frequently called on to perform certain motions which are not always those with which the musculo-skeletal structure of the body is comfortable. These motions, when repeatedly performed can result in a weakening of the supporting structure surrounding the joint. When a difficult motion is undertaken to an extreme, the joint undergoes a full dislocation. This situation requires a reduction of the joint to restore it to its normal condition. Each time a joint undergoes a full dislocation, the easier it is to have the situation repeat itself. This overall weakening also takes place in the case of partial dislocations where the received bone partially leaves the socket and thereafter returns to the proper position.
While certain joints in the human body are characterized by a deep socket, for example the socket formed in the pelvic bone to receive the head of the femur, there are other joints of the body which are designed for mobility rather than stability. These joints are characterized by relatively shallow socket. One such joint is the shoulder wherein the shallow socket (glenoid fossa) of the scapula receives the head of the humerus or upper arm bone. In athletics, this type of shallow-socket joint is frequently subjected to a motion, which coupled with an external force applied by either a competitor or contact with the ground, results in a partial dislocation or subluxation of the joint.
In the shallow glenohumeral shoulder joint, the mechanism of injury is typically an external rotation of the arm coupled with abduction or movement away from the body by the arm. The shoulder joint need not undergo a full dislocation, but often suffers a partial dislocation where the humerus or arm bone slides part way out of the joint and then moves back into place. As it is repeated, the tendency for it to occur again is greatly increased.
In contact sports such as football and hockey, the participants are equipped with a shoulder pad assembly. These pads cushion impact, but do little or nothing to prevent partial dislocations or subluxations of the shoulder. Consequently, athletes may have their upper torso wrapped with an elastic bandage prior to "putting on the pads." The Shoulder Spica is a well-known wrap that has been used to support the shoulder joint while still permitting use of the arm. The wrap is characterized by wrapping the upper arm and then taking the free end thereof across the chest, under the opposite arm, and behind the back. Three or more upper torso wraps are taken about the chest and back and down the upper arm. The free end is taped which decreases its effectiveness during an athletic workout or game since the wrap tends to loosen with use. Furthermore, the bulkiness of the wrap tends to reduce the field of other motions frequently limiting overall performance. To change the wrap is time-consuming. It requires the over-lying equipment to be removed since no adjustment can be made to the player without repeating the wrapping process.
As a substitute for the Shoulder Spica wrap, mechanical shoulder braces have been designed to assist football players in preventing shoulder subluxation. The braces provide motion inhibiting results when strapped to the torso. Hinged joints of the brace control the movement of the shoulder. These braces are cumbersome and quite expensive. Generally, they are beyond the budgetary abilities of most schools. Furthermore, the range of motion limitations of the brace provide freedom of movement up to the limit with no indication provided to the wearer of when the limit is about to be reached, i.e. no proprioceptive feedback is provided to the wearer. Consequently, the effectiveness of the athlete is reduced when the limit is abruptly reached.
A substitute for the mechanical brace with its hinged joint is the use of a fabric vest and attached half sleeve. Straps across the back and chest are used as stops to limit abduction while the cuff or half-sleeve on the upper arm serve to maintain the combination in position on the torso. The vest-sleeve combination establish limits to abductive movements, i.e. movements away from the central axis of the body, but does not provide any significant control of arm rotation. As a result, severe external rotation of the humerus in relation to the scapula can occur and subluxation is still a cause for concern.
Any device worn to reduce the chance of subluxation of the shoulder requires that resistance to external rotation and abduction be provided but to enhance the effectiveness to the wearer requires that the athlete be able to sense when the limits are being reached. An athlete sensing that he is approaching a limitation on permissible movement can alter his other movements so as to achieve his performance goal. The use of rigid confining harnesses alone or in combination with the fixed length tether of the fabric vest do establish a limit to movement, but fail to provide the athlete with notice that he is about to reach his limit. Without warning of the limit, hockey and lacrosse players raising their stick, or the football receiver extending his arms for the football do not have sufficient time to react and adjust. Thus, the existing orthotic devices decrease performance levels of the wearers.
Accordingly, an object of the present invention is the provision of an improved shoulder brace to reduce the possibility of subluxation. The invention is designed to indicate to the wearer when abduction and external rotation are approaching the limit for this individual so that overall movement can be adjusted to compensate. In addition, the present athletic brace is applied in combination with the conventional shoulder pad assembly when the assembly is in place. Consequently, individual adjustment can be made without requiring the wearer to shed pads and all.